This invention relates to knives generally carried in scabbards such as camping, hunting and hiking knives, and more particularly to such knives having interchangeable blades arranged to be put into and out of operative position selectively as desired.
Knives, and other generally similar tools having interchangeable blades and other implements are known in the art. Examples of such devices are illustrated in U.S. Pat. Nos. 300,858; 4,169,312; and 4,391,043. The latter two U.S. patents disclose knife constructions which utilize removable blades configured to be releasably attached to a handle member for individual use, and easily removable therefrom for installation of a replacement blade.
U.S. Pat. No. 300,858 discloses a construction more generally pertinent to the present invention for disclosing a tool having a handle member which rotatably mounts a double-ended blade having a cutting blade at one of its ends and a nut pick at its end opposite. Specifically, a handle member comprises two sapced apart lateral halves joined together at their rear end by a rivet. The forward end of the handle member includes a pivot which receives the intermediate portion of the blade for rotation of the blade 180.degree. about the axis of the pivot so that the nut pick or the blade may be contained within the confines of the handle member halves while the blade or nut pick projects outwardly therefrom for use. A cam and socket type stop arrangement is provided to releasably position the blade or nut pick to project from the handle member for use. An abutment stop is also provided at the rear end of the handle member and is configured for abutment by the nut pick to prevent rotation of the blade when downward force is applied to the blade during use and for abutment by the blade to prevent rotation of the nut pick when upward force is applied to it during use.
In all examples above, the knife constructions necessarily are somewhat complex and susceptible to wear and consequent failure. The latter two patents identified involve constructions which are susceptible to accidental release of the blade during use by inadvertent unlocking of the blade securing mechanism during manipulation of the knife. The first reference utilizes a construction which provides no positive locking arrangement which will reliably hold the blade in operative position when pressure is applied in any direction over than downwardly against the working surface of the knife blade, or will hold the nut pick in operative position when pressure is applied to it in any direction other than upwardly. In this regard, this knife arrangement presents a hazard to the user in that inadvertent rotation of the blade during use and even when carrying the knife can occur and cause the user serious cuts.